[Blood cultures--indication and antibiotic therapy].

Introduction: The purpose of this study was 1) to record the indication for obtaining blood cultures by registration of rectal temperature and presumed focus or symptoms 2) to register the choice of antibiotic therapy immediately after obtaining the blood culture and to relate it to the indication and 3) to evaluate the indication and choice of antibiotic therapy on the basis of the blood culture result.

Material And Methods: The study is a retrospective study of all blood cultures obtained at a department of internal medicine. In all 432 defined episodes, where blood cultures were obtained, the rectal temperature and the presumed focus or symptoms were registered.

Results: In 46.1% of the episodes the rectal temperature was below 38.5 degrees C. The most frequently presumed focus was the respiratory tract, accounting for 38.2%. Significant microorganisms were found in 50 episodes (11.6%) and in 14 (28%) of these the rectal temperature was below 38.5 degrees C. In 18 episodes (36%), the antibiotics used were inappropriate.

Discussion: It is difficult to define clearly the indication for obtaining blood cultures. There are many parameters to be considered, the rectal temperature being one of the most important, though not necessarily the decisive guideline. In many cases the presumed focus at the time of blood culture does not correspond well with the microorganism isolated later. It is therefore imperative to collect other relevant specimens in addition to blood and to make sure that the antibiotic therapy covers the most frequent types of infections and most serious aetiologies.